Storage tank sumps are used in the art to house or otherwise enclose various type of fluid transfer components (e.g., pumps, filters and the like) which are used to transfer liquids from an underground storage tank to above ground dispensers. In addition, storage tanks sumps are typically liquid tight, thereby reducing the risk of ground water pollution from liquid product spillage (e.g., gasoline and other petroleum distillates) which can occur when an underground storage tank holding the same is filled or the fluid transfer components housed with the storage tank sump are serviced or replaced. Typically, the underground storage tanks are placed on a pallet or concrete pad poured at the bottom of an excavated hole. Following attachment of the storage tank sump to the storage tank, the excavated hole is then back-filled and a driveway slab is poured over the top of the excavated hole.
While the fixed length storage tank sumps available in the art have been suitable for the purposes for which they were designed, heretofore there has not been available an adjustable length storage tank sump of simple construction having multiple sealing surfaces for accommodating a single easily replaceable seal. Further, heretofore there has not been available an adjustable length storage tank sump providing a structure for simply and quickly sealingly attaching a lid to the sump, wherein the structure attaching the lid is disposed outside of the sump sealing surfaces.